Membrane-based Energy Recovery Ventilators (ERV) are an effective means of reducing energy cost and allow for scaling down HVAC equipment. Owing to their compact geometry and rough surfaces of the porous membrane substrate@ ERV exchanger cores can be fouled by airborne particulate matter. In this study@ the influence of particulate fouling on the membrane-based ERVs was investigated via accelerated material- and core-level fouling experiments. The core-level experiments@ inside an Aerosol Wind Tunnel (AWT)@ investigated the effect of dust accumulation on the performance of cross-flow cores (including sensible and latent effectiveness@ and pressure drop) through comparing pre- and post-fouling performance tests of two core samples. The influence of the membrane surface exposed to particle-laden air@ and core face velocity were considered during AWT tests. We have found that for solid particles of 0.3?C10 ??@ deposition fractions to membrane surfaces range from ~0.05 at high air velocities (1 m/s (197 fpm)) to as high as 0.2 at lower air velocities (0.5 m/s (98 fpm)). Nevertheless@ accelerated fouling tests using coarse@ dry test dust (ISO A3 medium)@ did not show any significant degradation to the sensible and latent effectiveness of the cores. In the lack of proper filtration@ however@ this fouling may result in an energy penalty because of the added pressure drop in the system. Additionally@ a mass transport analysis is presented to explain the results of AWT tests. In the material-level experiments@ the effects of fouling with nano particles on the membrane material performance (including water vapor transport@ gas cross-over@ and pressurized air leakage) were examined. Preliminary results show that deposition of non-hygroscopic graphite particles has minimal influence on the membrane@ whilst deposition of soluble NaCl particles on the uncoated porous surface of the membrane may result in partial pore blockage@ consequently reducing the water vapor permeation through the membrane up to 15% of the initial value.